d1=k^21=p1=k^11=m1 is d2=k^22=k^12=m2 (default 1) myriads [tens of thousands of square kilometres] (area unit) measured in perpendicular directions (set)/defined by set of points (set) p2=m3 by standard m4.
The term has a particular use in connection with the British Ordnance Survey national grid and the US Military grid reference system.